Net CO2 assimilation rate (PN), stomatal conductance (gs), transpiration rate (E), and water use efficiency (WUE) in four perennial C3 species (grasses: Dactylis glomerata, Festuca rupicola, dicots: Filipendula vulgaris, Salvia nemorosa) grown for 231 d in open-top chambers at ambient (CA, 350 µmol mol-1) or elevated (CE, 700 µmol mol-1) CO2 concentrations were compared. When measured at CE, PN was significantly higher in CE plants of all four species than in the CA ones. The increase in PN was less prominent in the two grasses than in the two dicots. The E was significantly higher in the CE-grass F. rupicola and CE-dicot F. vulgaris than in the CA plants. There was no change in E owing to CE in the other grass and dicot. The gs in F. vulgaris and F. rupicola increased, while there was a decrease in D. glomerata and no change in S. nemorosa. WUE increased in all species grown in CE: four- to five-fold in the dicots and less than two-fold in the grasses. The increase in WUE was primarily due to an increase in PN and not to a decrease in E. and K. Szente, Z. Nagy, Z. Tuba.
We studied how tomato (Lycopersicon esculentum Mill.) chloroplast omega-3 fatty acid desaturase gene (Lefad7) overexpression enhanced low-temperature (LT) tolerance in transgenic tomato plants. In these plants, the content of linolenic acid (18:3) markedly increased and, correspondingly, the content of linoleic acid (18:2) decreased. Similar changes were found after 6 h under LT (4°C) treatment. Under LT stress, wild type (WT) tomato plants showed a much greater increase in relative electrolyte leakage and malondialdehyde (MDA) contents compared with transgenic plants. Transgenic plants exhibited higher activities of antioxidative enzymes and a lower content of reactive oxygen species (ROS). Transgenic plants maintained a relatively higher level of the net photosynthetic rate (PN) and chlorophyll (Chl) content than WT plants under LT stress. Taken together, we suggested that overexpression of Lefad7 enhanced LT tolerance by changing the composition of membrane lipids in tomato plants, with the increased content of trienoic fatty acids and reduced content of dienoic fatty acids that led to series of physiological alterations., X. Y. Liu ... [et al.]., and Obsahuje bibliografii
Two rice chlorophyll (Chl) b-less mutants (VG28-1, VG30-5) and the respective wild type (WT) plant (cv. Zhonghua No. 11) were analyzed for the changes in Chl fluorescence parameters, xanthophyll cycle pool, and its de-epoxidation state under exposure to strong irradiance, SI (1 700 µmol m-2 s-1). We also examined alterations in the chloroplast ultrastructure of the mutants induced by methyl viologen (MV) photooxidation. During HI (0-3.5 h), the photoinactivation of photosystem 2 (PS2) appeared earlier and more severely in Chl b-less mutants than in the WT. The decreases in maximal photochemical efficiency of PS2 in the dark (Fv/Fm), quantum efficiency of PS2 electron transport (ΦPS2), photochemical quenching (qP), as well as rate of photochemistry (Prate), and the increases in de-epoxidation state (DES) and rate of thermal dissipation of excitation energy (Drate) were significantly greater in Chl b-mutants compared with the WT plant. A relatively larger xanthophyll pool and 78-83 % conversion of violaxanthin into antheraxanthin and zeaxanthin in the mutants after 3.5 h of HI was accompanied with a high ratio of inactive/total PS2 (0.55-0.73) and high 1-qP (0.57-0.68) which showed that the activities of the xanthophyll cycle were probably insufficient to protect the photosynthetic apparatus against photoinhibition. No apparent difference of chloroplast ultrastructure was found between Chl b-less mutants and WT plants grown under low, LI (180 µmol m-2 s-1) and high, HI (700 µmol m-2 s-1) irradiance. However, swollen chloroplasts and slight dilation of thylakoids occurred in both mutants and the WT grown under LI followed by MV treatment. These typical symptoms of photooxidative damage were aggravated as plants were exposed to HI. Distorted and loose scattered thylakoids were observed in particular in the Chl b-less mutants. A greater extent of photoinhibition and photooxidation in these mutants indicated that the susceptibility to HI and oxidative stresses was enhanced in the photosynthetic apparatus without Chl b most likely as a consequence of a smaller antenna size. and Z.-F. Lin, G.-Z. Lin, C.-L. Peng.
Rationality requires you to intend to do what you believe you ought to do. This is a rough formulation of the requirement I call ''Enkrasia''. This article presents a precise formulation. It turns out to be complicated, and the article also explains the need for each complication., Racionalita vyžaduje, abyste měli v úmyslu dělat to, co si myslíte, že byste měli dělat. To je hrubá formulace požadavku, který nazývám ,,Enkrasia''. Tento článek představuje přesnou formulaci. Ukázalo se, že je to složité a článek také vysvětluje potřebu každé komplikace., and John Broome
Enteral nutrition (EN) is a preferred way of feeding in critically ill patients unless obvious contraindications such as ileus or active gastrointestinal bleeding are present. Early enteral nutrition as compared to delayed EN or total parenteral nutrition decreases morbidity in postsurgical and trauma patients. The hepatosplanchnic region plays a pivotal role in the pathophysiology of sepsis and multiple organ dysfunction syndrome. The beneficial effects of EN on splanchnic perfusion and energy metabolism have been documented both in healthy volunteers and animal models of sepsis, hemorrhagic shock and burns. By contrast, EN may increase splanchnic metabolic demands, which in turn may lead to oxygen and/or energy demand/supply mismatch, especially when hyperemic response to EN is not preserved. Therefore, the timing of initiation and the dose of EN in patients with circulatory failure requiring vasoactive drugs are a matter of controversy. Interestingly, the results of recent clinical studies suggest that early enteral nutrition may not be harmful even in patients with circulatory compromise. Nevertheless, possible onset of serious complications, the non-occlusive bowel necrosis in particular, have to be kept in mind. Unfortunately, there is only a limited number of clinically applicable monitoring tools for the effects of enteral nutrition in critically ill patients., R. Rokyta Jr., M. Matějovič, A. Kroužecký, I. Novák., and Obsahuje bibliografii
The information-theoretical entropy is an effective measure of uncertainty connected with an information source. Its transfer from the classical probabilistic information theory models to the fuzzy set theoretical environment is desirable and significant attempts were realized in the existing literature. Nevertheless, there are some open topics for analysis in the suggested models of fuzzy entropy - the main of them regard the formal aspects of the fundamental concepts. Namely their rather additive (i. e., probability-like) than monotonous (typical for fuzzy set theoretical models) structure. The main goal of this paper is to describe briefly the existing state of art, and to suggest and analyze alternative, more fuzzy set theoretical, approaches to the fuzzy entropy developed as a significant characteristic of the information sources, in the information-theoretical sense.
In my previous papers ([18], [19]) the entropy of fuzzy partitions had been defined. The concept of the entropy of a fuzzy partition was used to define the entropy of a fuzzy dynamical system and to propose an ergodic theory for fuzzy dynamical systems ([19], [20]). In this paper, using my previous results related to the entropy of fuzzy partitions, a measure of average mutual information of fuzzy partitions is defined. Some properties concerning this measure are proved. It is shown that the entropy of fuzzy partitions can be considered as a special case of their mutual information. We obtain that subadditivity and additivity of entropy of fuzzy partitions are simple consequences of these properties. The suggested measures can be applied whenever it is need to know the amount of information that we obtain by realization of experiments, the results of which are fuzzy events.
Uvažujeme skalární reakce-difúzní rovnice na ohraničených a rozšířených doménách, a to jak s autonomním, tak s časově periodickým nelineárním termínem. Diskutujeme význam a důsledky ergodické Poincaré-Bendixsonovy věty na dynamiku. Zejména ukazujeme, že v rozšířeném autonomním případě je časoprostorová topologická entropie nulová. Dále v rozšířeném neautonomním případě charakterizujeme časoprostorové topologické a metrické entropie jako entropie dvojice dojíždějících rovinných homeomorfismů.